Commit 61a35cfc authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: hold a request_queue reference for the lifetime of struct gendisk 



Acquire the queue ref dropped in disk_release in __blk_alloc_disk so any
allocate gendisk always has a queue reference.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816131910.615153-9-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4a1fa41d

block/genhd.c

+7 −12
Original line number Diff line number Diff line
@@ -551,15 +551,6 @@ void device_add_disk(struct device *parent, struct gendisk *disk, 
	register_disk(parent, disk, groups);

	blk_register_queue(disk);



	/*

	 * Take an extra ref on queue which will be put on disk_release()

	 * so that it sticks around as long as @disk is there.

	 */

	if (blk_get_queue(disk->queue))

		set_bit(GD_QUEUE_REF, &disk->state);

	else

		WARN_ON_ONCE(1);



	disk_add_events(disk);

	blk_integrity_add(disk);

}
@@ -1087,7 +1078,6 @@ static void disk_release(struct device *dev) 
	disk_release_events(disk);

	kfree(disk->random);

	xa_destroy(&disk->part_tbl);

	if (test_bit(GD_QUEUE_REF, &disk->state) && disk->queue)

	blk_put_queue(disk->queue);

	iput(disk->part0->bd_inode);	/* frees the disk */

}
@@ -1259,9 +1249,12 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, 
{

	struct gendisk *disk;



	if (!blk_get_queue(q))

		return NULL;



	disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);

	if (!disk)

		return NULL;

		goto out_put_queue;



	disk->bdi = bdi_alloc(node_id);

	if (!disk->bdi)
@@ -1296,6 +1289,8 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, 
	bdi_put(disk->bdi);

out_free_disk:

	kfree(disk);

out_put_queue:

	blk_put_queue(q);

	return NULL;

}

EXPORT_SYMBOL(__alloc_disk_node);

include/linux/genhd.h

+0 −1
Original line number Diff line number Diff line
@@ -149,7 +149,6 @@ struct gendisk { 
	unsigned long state;

#define GD_NEED_PART_SCAN		0

#define GD_READ_ONLY			1

#define GD_QUEUE_REF			2



	struct mutex open_mutex;	/* open/close mutex */

	unsigned open_partitions;	/* number of open partitions */